The way in which each country’s economy links to other countries is global economies
The answer would a , add period
If the underlined phrase is <em>having been warned by her mother, </em>then this is a nonessential perfect participial phrase.
Nonessential phrases are separated from the rest of the sentence by commas, and since this is a perfect participle, this is the only correct option.
Nervousness flows through our veins, This day has been dreaded since the news came